Commit 75932bcf authored by Agata Murawska's avatar Agata Murawska Committed by Iustin Pop
Browse files

Extend the ovf-support design with format translation


Signed-off-by: default avatarAgata Murawska <agatamurawska@google.com>
Signed-off-by: default avatarIustin Pop <iustin@google.com>
Reviewed-by: default avatarIustin Pop <iustin@google.com>
parent c2a0947d
......@@ -44,7 +44,7 @@ i.e. CIM - Common Information Model) format is accepted, although
there is no guarantee that every virtualization software will support
all types of hardware.
OVF package should contain one file with .ovf extension, which is an
OVF package should contain one file with ``.ovf`` extension, which is an
XML file specifying the following (per virtual machine):
- virtual disks
......@@ -52,7 +52,7 @@ XML file specifying the following (per virtual machine):
- list of virtual hardware
- operating system, if any
Each of the elements in .ovf file may, if desired, contain a
Each of the elements in ``.ovf`` file may, if desired, contain a
human-readable description to every piece of information given.
Additionally, the package may have some disk image files and other
......@@ -92,6 +92,116 @@ The conversion between RAW and the other formats will be done using
qemu-img, which transforms, among other, raw disk images to monolithic
sparse vmdk images.
Import and export - the closer look
===================================
This section contains an overview of how different parts of
Ganeti's export info are included in ``.ovf`` configuration file.
It also explains how import is designed to work with incomplete
information.
Ganeti's backup format vs OVF
-----------------------------
.. highlight:: xml
The basic structure of Ganeti ``.ovf`` file is the following::
<Envelope>
<References></References>
<DiskSection></DiskSection>
<NetworkSection></NetworkSection>
<VirtualSystem>
<Name></Name>
<OperatingSystemSection></OperatingSystemSection>
<VirtualHardwareSection><VirtualHardwareSection>
</VirtualSystem>
<gnt:GanetiSection>
<gnt:VersionId/>
<gnt:AutoBalance/>
<gnt:Tags></gnt:Tags>
<gnt:OSParameters></gnt:OSParameters>
<gnt:Hypervisor>
<gnt:HypervisorParameters>
</gnt:HypervisorParameters>
</gnt:Hypervisor>
</gnt:GanetiSection>
</Envelope>
.. note ::
Tags with ``gnt:`` prefix are Ganeti-specific and are not a part of
OVF standard.
.. highlight:: text
Whereas Ganeti's export info is of the following form, ``=>`` showing
where will the data be in OVF format::
[instance]
disk0_dump = filename => References
disk0_ivname = name => ignored
disk0_size = size_in_mb => DiskSection
disk_count = number => ignored
disk_template = disk_type => References
hypervisor = hyp-name => gnt:HypervisorSection
name = inst-name => Name in VirtualSystem
nic0_ip = ip => Item in VirtualHardwareSection
nic0_link = link => Item in VirtualHardwareSection
nic0_mac = mac => Item in VirtualHardwareSection
nic0_mode = mode => Network in NetworkSection
nic_count = number => ignored
tags => gnt:Tags
[backend]
auto_balanced => gnt:AutoBalance
memory = mem_in_mb => Item in VirtualHardwareSection
vcpus = number => Item in VirtualHardwareSection
[export]
compression => DiskSection
os => OperatingSystemSection
source => ignored
timestamp => ignored
version => gnt:VersionId
[os] => gnt:OSParameters
[hypervisor] => gnt:HypervisorParameters
In case of multiple networks/disks used by an instance, they will
all be saved in appropriate sections as specified above for the first
network/disk.
Import from other virtualization software
-----------------------------------------
In case of importing to Ganeti OVF package generated in other software,
e.g. VirtualBox, some fields required for Ganeti to properly handle
import may be missing. Most often it will happen that such OVF package
will lack the ``gnt:GanetiSection``.
If this happens, the tool will simply ask for all the necessary
information or otherwise you can specify all the missing parameters in
the command line. For the latter, please refer to [TODO: reference to
command line options]
Export to other virtualization software
---------------------------------------
When exporting to other virtualization software, you may notice that
there is a section ``gnt:GanetiSection``, containing Ganeti-specific
information. This may on **rare** cases cause trouble in importing your
instance. If that is the case please do one of the two:
1. Export from Ganeti to OVF with ``--external`` option - this will
cause to skip the non-standard information.
2. Manually remove the gnt:GanetiSection from the ``.ovf`` file. You
will also have to recompute sha1 sum (``sha1sum`` command) and update
your ``.mf`` file with new value.
.. note::
Manual change option is only recommended when you have exported your
instance with ``-format`` option other that ``raw`` or selected
``--compress``. It saves you the time of converting or compressing
the disk image.
Planned limitations
===================
......@@ -107,8 +217,8 @@ Package
-------
There are no limitations regarding support for multiple files in
package or packing the ovf package into one OVA (Open Virtual
Appliance) file. As for certificates and licenses in the package,
package or packing the OVF package into one OVA (Open Virtual
Appliance) file. As for certificates and licenses in the package,
their support will be under discussion after completion of the basic
features implementation.
......@@ -129,9 +239,9 @@ As mentioned, Ganeti will allow exporting only ``raw``, ``cow`` and
``raw``, ``cow``, ``qcow``, ``qcow2``, ``vmdk`` and ``cloop``. We do
not plan for now to support ``vdi`` or ``vhd``.
We support compression both for import and export - for export this
will use ovftools with chosen level of compression. There is also a
possibility to provide virtual disk in chunks of equal size.
We plan to support compression both for import and export - in tar.gz
format. There is also a possibility to provide virtual disk in chunks
of equal size.
When no ``ovf:format`` tag is provided during import, we assume that
the disk is to be created on import and proceed accordingly.
......@@ -154,6 +264,7 @@ TODO
Other
-----
Implementation details
======================
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment